A triangle has sides A,B, and C. If the angle between sides A and B is #(pi)/3#, the angle between sides B and C is #pi/6#, and the length of B is 9, what is the area of the triangle?

1 Answer
Dec 28, 2015

17.537

Explanation:

As the sum of all the angles of a triangle is #180^0# or #pi# radians
So, from your sum it can be seen that the third angle between A and C #=pi-pi/3-pi/6=pi/2#
Thus making the side B, which is opposite to the #90^0# angle hypotenuse of the triangle.
So, the area of the triangle would be #1/2*base*height=1/2*A*C#
Given that side #B=9#, we can find the other two side by triangle geometry
#A=B*cos(pi/3)=9*cos(pi/3)=4.5#
#C=B*sin(pi/6)=9*sin(pi/6)=7.794#
Hence, #Area=1/2*A*C=1/2*4.5*7.794=17.537#